JP2011520765A - Porous ceramic plate having asymmetric pore structure and manufacturing method thereof - Google Patents

Abstract

  According to the present invention, a method for continuously producing a porous ceramic plate having asymmetric pores comprises heat treating the ceramic particles and the expansion agent in a foaming furnace while conveying the ceramic particles and the expansion agent at a first speed, The porous ceramic plate is cooled by cooling the porous ceramic plate in a slow cooling pot for annealing while the porous ceramic plate is conveyed at a second speed higher than the first speed. Annealing the porous ceramic plate and stretching and cooling the porous ceramic plate.

Description

  The present invention relates to a continuous production method and production apparatus for a porous ceramic product (for example, a porous ceramic plate such as a foamed glass plate). Moreover, this invention relates to the porous ceramic product obtained by the said manufacturing method.

There are various methods for producing a porous ceramic material including a foaming step. Examples include the following methods:
a) Gas is inserted into the low-viscosity melt (for example, taken up by injection) and mechanically blended.
b) releasing and expanding gas in a low viscosity melt under vacuum.
c) Insert (incorporate) a blowing agent into the melt.
d) The glass powder is mixed with the blowing agent and subsequently heated.

  In the case of the last glass foaming method, the production apparatus usually includes a foaming furnace having a belt for conveying glass powder and foam, and a powder loading device. The foaming step includes a step of foaming a thick plate or a thin plate.

  The present invention has been found because stretching a porous ceramic product (eg, foam glass) during the manufacturing process changes the physical properties of the final material, such as the thermal insulation of the porous ceramic product (eg, foam glass). It has been done. Thereby, various physical properties can be improved. This is beneficial in that it allows glass properties tailored to customer needs (e.g., lowering thermal conductivity, i.e. improving insulation properties).

In a first aspect, the present invention relates to a continuous manufacturing method of a porous ceramic plate (for example, a single-type ceramic plate). The above manufacturing method is:
a) heat-treating the ceramic particles and the expansion agent in a foaming furnace while conveying the ceramic particles and the expansion agent at a first speed to form a porous ceramic plate;
b) The porous ceramic plate is annealed by cooling the porous ceramic plate in an annealing slow cooling pot while the porous ceramic plate is conveyed at a second speed higher than the first speed. Stretching and cooling the porous ceramic plate.

  In the first embodiment, before the step (b), the present invention provides a third speed higher than or equal to the second speed from the foaming furnace to the annealing cooler via the intermediate conveyor. It relates to a method of transporting a (single-sheet) porous ceramic plate. This is advantageous in that the porous ceramic plate can be stretched in a relatively high temperature region without requiring an annealing treatment conveyor (second conveyor) that is resistant to a relatively high temperature. Stretching at a relatively low temperature results in greater stress in the foam than stretching at a relatively high temperature.

  It is preferable to change only an intermediate conveyor shorter than the annealing conveyor (for example, very short) so as to be resistant to a relatively high temperature. Since the annealing process requires a relatively long conveyor, it is economical to use an annealing conveyor that is not resistant to relatively high temperatures (eg, when using an intermediate conveyor, the second conveyor The upper limit temperature of 600 ° C. is sufficient for the resistance of the conveyor, and it is not necessary to use a second conveyor having an upper limit temperature of 800 ° C. or 900 ° C. in a long annealing slow cooling pot.

  In the first aspect, in the method according to the present invention, the difference between the second speed and the first speed is preferably 25% or less of the first speed, preferably 1% or more and 25% or less. % Or more and 20% or less is more preferable, and 3% or more and 15% or less is most preferable. By stretching in the above range, it is possible to improve the heat insulation (lower K-value) while simultaneously keeping the amount of damage relatively low. Usually, it is useful to increase the stretching temperature in order to reduce breakage due to large speed differences.

  In the first aspect, in the method according to the present invention, the difference between the third speed and the second speed is 0% or more and 10% or less (or 1% or more and 10% or less), and 0% or more, It is preferably 5% or less (1% or more and 5% or less). By stretching the single-type porous ceramic plate to some extent in advance, the porous ceramic plate can be shrunk during the annealing treatment, and it is beneficial because stress can be released and cracks can hardly occur.

  In the first aspect, the present invention relates to a method wherein the elongation is 3% or more and 15% or less. Forming the porous ceramic plate so that it has at the same time acceptable compressive strength and improved thermal insulation properties compared to other unstretched identical porous ceramic plates by having the stretch in the above range It is beneficial in that it can. In the first aspect, in the method according to the present invention, the porous ceramic plate may be a foamed glass plate.

In the foaming process, open cells or closed cells may be generated. Closed cells are more preferable from the viewpoint of insulation. In the case of foamed glass, open cells are obtained by adding a crystalline material (such as TiO ₂ ) to the amorphous glass powder. For example, adding about 1% TiO ₂ while grinding the glass (eg in a ball mill) can produce 100% open cells in the glass foam. When closed cells are required, it is preferable to avoid the addition of TiO ₂ or similar crystalline materials.

In the second embodiment, the continuous production apparatus for a porous ceramic plate according to the present invention is:
a) a foaming furnace that heat-treats the ceramic particles and the expansion agent to form a porous ceramic plate during conveyance at the first speed;
b) The porous ceramic plate is annealed by cooling the porous ceramic plate while the porous ceramic plate is conveyed at a second speed higher than the first speed, and the porous ceramic plate And an annealing slow-cooling pot for stretching and cooling.

In other words, the second embodiment of the continuous production apparatus for porous ceramic plates according to the present invention is:
a) a foaming furnace for heat treating the ceramic particles and expansion agent to form a porous ceramic plate;
The foaming furnace includes a first conveyor adapted to transport at a first speed (in other words, a linear speed) while heating the ceramic particles and the expansion agent to form the porous ceramic plate,
b) including an annealing slow cooling pot for annealing the porous ceramic plate by cooling the porous ceramic plate;
The annealing slow-cooling pot is located downstream from the foaming furnace, and is adapted to transport the porous ceramic plate at a second speed (in other words, a linear speed) faster than the first speed. Including conveyor.

  In order to obtain a second linear velocity higher than the first linear velocity, the first conveyor and the second conveyor may be provided with independent drive means. In a second embodiment, the apparatus is configured to place the porous ceramic plate before the second conveyor from the first conveyor (for example, from a foaming furnace) to the second conveyor (for example, from an annealing annealing pot). It further includes an intermediate conveyor for movement. By the presence of the intermediate conveyor between the first conveyor and the second conveyor, it is possible to use a second conveyor having a lower heat resistance than when the second conveyor is directly adjacent to the first conveyor. . Considering the relatively long point of the second conveyor when compared with the intermediate conveyor, it can be said that it is particularly preferable from the viewpoint of reducing the cost per unit length of the second conveyor.

  In the second mode in which an intermediate conveyor is present, the intermediate conveyor may be adapted to a third linear speed that is faster than or equal to the second speed. In other words, the intermediate conveyor can operate at a third speed that is faster than or equal to the second speed. This is advantageous in that the porous ceramic plate can be stretched in a relatively high temperature region without requiring an annealing treatment conveyor (second conveyor) resistant to a relatively high temperature. is there. By stretching at a relatively high temperature, the stress can be made smaller than when stretching at a relatively low temperature. In order to realize a third linear velocity higher than the second velocity, an independent drive means may be provided on the third conveyor.

  In the second embodiment of the present invention, the difference between the second speed and the first speed is 25% or less of the first speed, preferably 1% or more and 25% or less, more preferably 2% or more, The first conveyor and the second conveyor may be adapted to be driven so as to be 20% or less, and most preferably 3% or more and 15% or less.

  In other words, the first conveyor and the second conveyor are driven so that the difference between the second speed and the first speed is 25% or less of the first speed, preferably 1% or more and 25% or less. Also good. An embodiment in which the difference between the second speed and the first speed is 5% or more and 25% or less is also possible.

  In the second embodiment in which the intermediate conveyor is present, the difference between the third speed and the second speed is 0% or more and 10% or less, and preferably 0% or more and 5% or less.

  In the second embodiment according to the present invention, the first conveyor may be adapted to a higher temperature resistance than the second conveyor. This configuration is beneficial because the temperature in the foamed region is higher than the temperature in the annealed region.

  In the second embodiment according to the present invention, the first conveyor may be adapted to a temperature resistance having an upper limit of 800 ° C, preferably an upper limit of 900 ° C. Further, the second conveyor may be adapted to a temperature resistance with an upper limit of 600 ° C. These temperatures are usually the maximum temperatures in the foaming process and the annealing process, respectively.

  In the second embodiment of the present invention, the intermediate conveyor may be composed of rolls. The preferred distance between the two rolls can be changed according to the action of many physical properties, and is preferably set by trial and error. Usually, the distance can be 0.2 m or more and 1.5 m or less. An embodiment in which the distance between the two rolls is 0.2 m or more and 0.4 m or less is also possible. In the embodiment, the distance between the two rolls can be at least 0.8 m and 1.5 m or less.

  By being within the above range, the distance can be made sufficiently long so that the number of rolls can be reduced and the number in the friction region between the porous ceramic plate and the conveyor can be reduced. This friction produces dust. The greater the distance between the two rolls, the greater the risk of stagnation when the porous ceramic plate is damaged. Roll conveyors are preferred, are easier to manufacture than belt conveyors, and are less prone to stagnation of damaged porous ceramic plates when used at relatively high temperatures (especially 450 ° C. for foamed glass).

  In the second embodiment according to the present invention, the intermediate conveyor is disposed in the head portion of the annealing slow cooler or in the intermediate slow cooler disposed between the foaming furnace and the annealing slow cooler. Also good.

  For example, when there is no intermediate (third) conveyor, between the first conveyor and the second conveyor, or when there is an intermediate conveyor, between the first conveyor and the intermediate (third) conveyor. It is beneficial to adapt the device so that there is substantially no temperature gradient in the region of the device where elongation occurs (eg, at least perpendicular to the direction of transport). In this way, crushing of the porous ceramic plate during or after production is minimized.

  In the second embodiment according to the present invention in which an intermediate conveyor is present, the intermediate (third) conveyor is temperature resistant within a range of 600 ° C. to 800 ° C., preferably 600 ° C. to 900 ° C. You may have.

  This allows the intermediate (third) conveyor to transition with higher reliability between the first conveyor and the second conveyor.

  In a third aspect, the present invention relates to a porous ceramic plate having a pore structure. Since the porous ceramic plate has a pore structure, each pore is asymmetric, and each pore is, for example, elongated.

  In an embodiment, the average of the longest dimension (eg, length) of the pores is at least longer than the shortest dimension (eg, dimension (height) in a direction perpendicular to the surface of the porous ceramic plate) of the pores. Good. In the embodiment of the present invention, the ratio between the average maximum dimension of pores and the average minimum dimension of pores may be 1.2 or more and 2.5 or less. It has been found that the average ratio is 1.2 or more and 1.6 or less as a condition that can achieve a trade-off relationship between the insulation characteristics and the mechanical characteristics.

For the purposes of the present invention, the difference in length between the average maximum dimension and the average minimum dimension is measured by an ultrasonic measurement method. For example, ultrasonic transmission measured in the length direction (direction of conveyance and extension in the ultrasonic transmission time) relative to the ultrasonic transmission time measured in the height direction (perpendicular to the surface of the glass foam) The ratio of time has been found to be about 1.4 for the glass foam to exhibit a thermal conductivity of 0.042 W / mK at 10 ° C. at a density of 115 kg / m ³ .

  In the third embodiment, the porous ceramic plate may have an asymmetric pore structure and may be obtained by any of the methods according to the first embodiment of the present invention.

  In a third form, the porous ceramic plate may be a glass foam and / or a closed cell foam.

FIG. 1 schematically shows an apparatus according to an embodiment of the invention.

  Although the present invention will be described with reference to specific examples, the present invention is not limited to the specific forms described above. Exactly the scope of the invention is limited only by the appended claims. In the claims, 'comprising' does not exclude the presence of other elements or steps. Moreover, although various features may be included in different claims, they may be preferably combined and are not meant to be included and / or preferred in different claims. Furthermore, a single relationship does not exclude a plurality of relationships. Accordingly, the notation “singular form”, “first”, “second” and the like does not exclude a plurality of expressions. Furthermore, the member numbers in the claims do not limit the scope.

Definition:
The type of “porous ceramic” is not limited to carbon foam, but includes glass foam and cellular concrete. Glass foam has a combination of unique properties, stiffness, compressive strength, thermal insulation, non-flammability, chemical inertness, water / steam resistance, insect / rodent resistance It is usually lightweight. The glass foam is usually formed by a gas generating agent (for example, foaming). The glass generator is mixed with powdered glass (for example, glass particles). This mixture is heated to a temperature at which gas release from the blowing agent occurs within the softened glass.

The released gas produces bubbles that form pores (for example, pores) in the final glass foam. The porous ceramic according to the present invention is 2% or more and 45% or less, preferably 3% or more and 25% or less, most preferably 4% or more and 10% of the density corresponding to the intact (non-porous) ceramic. It has the following density. If foam glass, the density of the glass is preferably 50 Kg / ^{m 3} or more, 1000 Kg / ^{m 3} or less, more preferably an amount of 75 kg / ^{m 3} or more, 600 Kg / ^{m 3} or less, and most preferably 90 Kg / ^{m 3} or more, 250 Kg / ^{m 3} or less, or, 100 Kg / ^{m 3} or more and 250 Kg / ^{m 3} or less.

  For example, in connection with a porous ceramic plate, unless otherwise specified herein, the term 'plate' relates to a three-dimensional object and is wider than thickness and any length. In the relationship with the first embodiment according to the present invention, the wording 'plate' relates to a continuous single-sheet plate after the annealing process or until it is finally cut. Further, the wording 'plate' used in connection with the third embodiment according to the present invention is one of the continuous single plate or the short plate after the continuous plate is cut in the lateral direction. It is related to.

  Unless otherwise specified herein with respect to the temperature applied to the conveyor, the word 'resistant' means that the conveyor does not substantially deform when exposed to the temperature for an extended period of time. For example, when the conveyor is a belt conveyor, the elongation of the belt is preferably 1% or less under the condition of 120 days at the above temperature.

  The above-mentioned foaming furnace used in the disclosure of the present invention means a furnace in which a porous ceramic (for example, foamed glass) is manufactured.

  In a first aspect, the present invention relates to a continuous manufacturing method of a porous ceramic plate (single-type ceramic plate). The continuous production means production of a single (continuous) porous ceramic plate in contrast to, for example, a batch production method such as a molding method.

  In the continuous manufacturing method according to the first aspect of the present invention, the porous ceramic plate having a single structure is cut into a plate having a specific length and manufactured at the end of the annealing process or after the annealing process. .

In an embodiment according to the present invention, the manufacturing method includes:
(A) heat treating the ceramic particles and the expansion agent in a foaming furnace to form a porous ceramic plate;
And (b) annealing the porous ceramic plate by cooling the porous ceramic plate in the annealing cooler. In a preferred embodiment, the porous ceramic plate is a foam glass plate.

  In an embodiment, the heat treatment raises the temperature of the ceramic particles and the expansion agent to a sufficiently high temperature to form a porous ceramic material. For example, in the case of a foam glass plate, this temperature is 650 ° C. or more and 850 ° C. or less, preferably 700 ° C. or more and 800 ° C. or less. The ceramic particles may be of any shape, size or aspect ratio known to those skilled in the art that a porous ceramic body can be produced.

  The specific surface area of the ceramic particles measured by Brunauter Emmett Teller (BET) analysis is preferred. The foaming agents that can be used in the first embodiment according to the present invention include known foaming agents that can be used technically for the production of porous ceramic bodies. These blowing agents include, but are not limited to, carbon black and carbonates (eg, calcium carbonate or sodium carbonate).

  The ratio of the foaming agent to the ceramic particles can be any known ratio capable of technically producing a porous ceramic body. Preferably, it is 0.1% or more and 2% or less. In the case of carbon black, it is preferably 0.2% or more and 0.6% or less, particularly preferably 0.3% or more and 0.5% or less. In the case of carbonate, it is preferably 0.7% or more and 1.3% or less, more preferably 0.8% or more and 1.2% or less.

  In the embodiment according to the present invention, the annealing process may be a process of slowly decreasing the temperature according to a defined temperature profile.

  Although this is not the purpose of the present invention, the temperature profile of the overall foaming and annealing process affects the state of defects in the foamed glass product obtained by the stretching process described above. This fine adjustment of the temperature profile is a problem to be solved by trial and error, and is solved without requiring excessive experimental effort within the knowledge of those skilled in the art. Usually, the purpose of these temperature profiles is to mitigate to reduce residual strain with small temperature gradients. It is effective that a gradual temperature change is made in different areas.

  In a preferred embodiment of the first aspect according to the present invention, the step (a) is preferably a step of forming a porous ceramic plate, while the ceramic particles and the expansion agent are conveyed at the first speed. In addition, the step (b) is performed while the porous ceramic plate obtained in the step (a) is conveyed at a second speed higher than the first speed, and the porous ceramic plate is stretched and cooled. It is preferable that it is a process to perform.

  Depending on the foamed ceramic material and the thickness of the plate produced, the first speed can be in the range of 1 cm / min to 100 cm / min, for example. Moreover, as an example, in one embodiment, it is 1 cm / min or more and 15 cm / min or less. In the embodiment according to the present invention, the first conveyor that transports the foam in the first foaming region is used, and the second conveyor that transports the foam at the second speed higher than the first speed in the annealing treatment region. By using it, it is possible to stretch a porous ceramic foam, for example a glass foam.

  In the embodiment of the present invention, the speed of the second conveyor, that is, the speed of the annealing conveyor is higher than the speed of the foaming conveyor (that is, the first conveyor). In particular, during the start of production (e.g. when production is interrupted and resumption is required), the speed of the second conveyor in the slow cooling kettle is much faster (e.g. 3%) than the first conveyor in the foaming zone. Thus, it is very preferable to make it 20% or less faster, preferably 4% or more and 20% or less faster, more preferably 7% or more and 20% or less faster (for example, 8% or more faster).

  After production has begun, the speed of the second conveyor can be reduced to, for example, about 3%. The difference between the first speed and the second speed is preferably 25% or less, more preferably 3% or more and 25% or less, or 5% or more and 25% or less. As an example, if the upper limit is made up to 20%, for example, 10%, a decrease in K-value and a decrease in compressive strength can be seen by stretching unbroken glass foam yarn. In the embodiment according to the present invention, the expansion / contraction is preferably 3% or more and 25% or less (for example, 5% or more and 25% or less).

  In the embodiment according to the present invention, the foam is stretched by using separate conveyors of a foaming conveyor and a foamed glass annealing treatment conveyor.

  In the embodiment of the first aspect according to the present invention, the porous plate is transported from the foaming furnace to the annealing cooler by the intermediate conveyor before the step (b) and after the step (a). Preferably, the intermediate conveyor is transported at a third speed that is faster than or equal to the second speed. Preferably, the difference between the third speed and the second speed is 0% or more and 10% or less of the second speed.

  In another embodiment according to the present invention, the intermediate conveyor (for example, if the intermediate conveyor includes rolls, the intermediate conveyor roll) is set to the first conveyor so that the linear speed of the intermediate conveyor is equal to that of the second conveyor. You may connect with 2 conveyors. As a result, stretching occurs at a higher temperature location between the first conveyor (eg, foaming belt) and the intermediate conveyor (eg, the first roll of the intermediate conveyor).

  As an accompanying feature, by using the speed of the intermediate conveyor, the foam can be pre-stretched between the first conveyor and the intermediate conveyor. The speed of the intermediate conveyor is less than a few percent of the second speed. Value (eg between 1% and 10%, eg 5%). The second speed is faster than the value in the annealing furnace. Thereby, the said foam can be shrunk in a slow cooling pot, and final expansion | extension is expansion | extension by the speed difference of a 1st conveyor and a 2nd conveyor. Stress and breakage are reduced by shrinkage of the porous ceramic material in the slow cooling kettle.

  For all the embodiments according to the first aspect of the present invention, the temperature distribution in the width direction of the porous ceramic plate is preferably as uniform as possible in the region where the expansion occurs. The temperature distribution in the width direction of the porous ceramic plate extends to 20 ° C. or less in the region where the elongation occurs. This can be seen as follows. For example, it can be seen by isolating the area from other devices (other than drafts (eg, venting and exhausting gas flow)) and / or adapting the heater location to the individual temperature controls.

  In embodiments, the area where stretching occurs (eg, the area between the first conveyor and the intermediate conveyor) is adapted so that a minimal flow is applied locally. According to this technique, a plurality of regions are directly arranged upstream or downstream from the region where expansion occurs. Thereby, more wind can be applied than the said area | region where expansion | extension occurs.

  In a second aspect, the present invention relates to an apparatus used for a continuous production method of a porous ceramic plate. The apparatus is adapted to perform the manufacturing process according to the first embodiment. The apparatus according to the present invention includes a foaming furnace and a annealing cooler for annealing. The foaming furnace is suitable for heat treatment of ceramic particles and expansion agent. What is necessary is just to change processing temperature according to the property of the particle | grains to be used. In the case of glass particles, the treatment temperature can be 600 ° C. or more and 950 ° C. or less, preferably 650 ° C. or more and 800 ° C. or less during most of the foaming step. The annealing furnace for annealing is suitable for annealing a porous ceramic plate by cooling the porous ceramic plate in a controlled manner. The annealing furnace for annealing is located upstream or downstream from the foaming furnace. The apparatus also includes at least two conveyors: a first conveyor and a second conveyor. The conveyor used for foaming is hereinafter referred to as a first conveyor. The first conveyor is disposed in a foaming area (for example, the foaming area includes the foaming furnace). A suitable conveyor for this purpose is an endless metal belt filled with openings with a suitable ceramic material. The conveyor used in the annealing process is hereinafter referred to as a second conveyor. The second conveyor is included in the annealing furnace for annealing. A suitable conveyor for the annealing bath can be, for example, a belt or a roll.

  The length of the foaming conveyor can be, for example (in the case of glass foam) 35 m or more and 75 m or less, for example 45 m or more and 55 m or less. The length of the conveyor for annealing treatment can be, for example (in the case of glass foam), 150 m or more and 300 m or less, and preferably 200 m or more and 280 m or less. Typically, these dimensions are shortened or lengthened by slowing or increasing the respective transport speed. Therefore, very short dimensions (see test size lines in examples below) or very long dimensions can be used. In the embodiment according to the present invention, the ratio of the length of the second conveyor to the length of the first conveyor is 2 or more and 8 or less.

  In a preferred embodiment of the second aspect of the invention, the first conveyor transports at the first speed while the second conveyor is adapted to transport at a second speed higher than the first speed. Have been adapted. Preferably, the difference between the second speed and the first speed is 25% or less of the first speed, preferably 1% or more and 25% or less, and most preferably 3% or more and 5% or less. The first conveyor and the second conveyor are adapted to be driven.

  In the embodiment, this difference can be 5% or more and 25% or less. In the embodiment according to the present invention, the extension includes the speed of the second conveyor being higher than the speed of the first conveyor, and therefore, the slow cooling kettle can be made longer than the case where the extension is not performed. If 20% stretching is required, it is preferable to use a second conveyor that is 20% longer. In other words, the length of the conveyor is preferably proportional to the required extension.

  The aspect of the 2nd form which concerns on this invention WHEREIN: It is preferable that the said 1st conveyor is adapted to the temperature tolerance higher than a 2nd conveyor. The first conveyor may be adapted to have a temperature resistance of an upper limit of 800 ° C, an upper limit of 900 ° C, or an upper limit of 950 ° C. A suitable first conveyor may be, for example, a metal mesh belt filled with a suitable ceramic (eg, a ceramic that is resistant to the above temperature without substantially shrinking).

  In the case where no intermediate conveyor is used between the first conveyor and the second conveyor, it is further preferable that the second conveyor has a resistance to a high temperature of 800 ° C, preferably 900 ° C. Moreover, when using an intermediate | middle conveyor between a 1st conveyor and a 2nd conveyor, it is still more preferable that the said 2nd conveyor has tolerance with respect to low temperature (for example, an upper limit is 600 degreeC). In embodiments where an intermediate conveyor is used, the second conveyor may be adapted to be resistant to temperatures up to 600 ° C.

  The second conveyor is relatively long, and the temperature at the end of the foaming region (for example, a foaming furnace) is relatively high (in the case of a glass foam plate, the upper limit is 800 ° C., or the upper limit is 900 ° C. or the upper limit is 950 ° C). It is advantageous if an intermediate conveyor that is resistant to relatively high temperatures (eg, 600 ° C. or more and 800 ° C. or less) is between the foamed region and the annealing conveyor. Here, in one embodiment according to the present invention, it is preferable that one or more intermediate conveyors are used between the first conveyor and the second conveyor. In the aspect according to the second embodiment of the present invention, the apparatus further includes a third conveyor (referred to as intermediate conveyor (s) in the following description).

  A single intermediate conveyor is preferably used, and the following description refers to a single intermediate conveyor, but may be modified to provide a plurality of intermediate conveyors. Due to the presence of the intermediate conveyor, it may have low heat resistance, and therefore, an inexpensive second conveyor (for example, one having only heat resistance of 600 ° C. or less in the production of a glass foam plate) may be used. Is possible. This is particularly effective in view of the relatively long length of the second conveyor and the high cost. The intermediate conveyor is preferably adapted to carry at a third speed that is faster than or equal to the second speed. In an embodiment according to the present invention, a separate driving system is provided on the intermediate conveyor (for example, a roll of the intermediate conveyor). As a result, the facility can produce a linear speed of the intermediate conveyor that is different from the speed of the first conveyor or the second conveyor. More preferably, the difference between the third speed and the second speed is 0% or more and 10% or less, preferably 0% or more and 5% or less.

  In a preferred embodiment according to the present invention, when an intermediate conveyor including rolls is used between the first conveyor and the second conveyor, the roll is equal to the conveyance speed of the intermediate conveyor or the conveyance speed of the second conveyor. The upper limit may be driven at a speed 10% faster, preferably 5% faster. The intermediate conveyor is preferably in the range of 600 ° C. or higher and 800 ° C. or lower, that is, the upper limit is 800 ° C., and preferably the upper limit is 850 ° C.

  The length of the intermediate conveyor is, for example, 2% or more and 30% or less of the length of the second conveyor, preferably 3% or more and 20% or less of the length of the second conveyor. The intermediate conveyor preferably includes a roll. Thereby, when the ceramic (for example, glass) is at a temperature at which the viscoelasticity is sufficiently high, the formation becomes easy and inexpensive, and breakage hardly occurs due to the inclusion of the roll. The preferable distance between the two rolls is preferably determined by trial and error in consideration of many physical properties. Usually, it can be 0.2 m or more and 1.2 m or less. A preferable distance is 0.2 m or more and 0.4 m or less, and in some embodiments, it can be used at 0.6 m or more and less than 1.5 m, and in other embodiments, 0.8 m or more, and 1. Less than 2m is used. Furthermore, in other embodiments, 0.9 m and 1.2 m can be used.

  In some embodiments, the preferred value has been found to be 0.3 m, and in other embodiments, the preferred value has been found to be 1 m. The intermediate (third) conveyor is disposed in front of (for example, upstream) the second conveyor, and is located at the top of the annealing slow cooling pot or between the foaming region / furnace and the annealing slow cooling pot. It is preferable that it is located in the intermediate slow cooling pot arrange | positioned in (3). The intermediate conveyor is suitable for conveying the porous ceramic plate from the foaming furnace to the annealing cooler.

  In the embodiment according to the present invention, it is preferable that a lateral temperature gradient (temperature difference across the porous ceramic plate) in which expansion and contraction does not occur. The lateral temperature gradient (temperature difference across the porous ceramic plate) at which expansion and contraction occurs is preferably 20 ° C. or less. This condition can be achieved, for example, by installing a heater having a separate temperature control device at an appropriate location.

  In a third aspect, the present invention relates to a porous ceramic plate having an asymmetric pore structure. The porous ceramic plate obtained in the method according to the first embodiment is a single-plate continuous plate. The single-sheet continuous plate may be cut to a desired size after the annealing process or at the end of the annealing process. Due to stretching, the properties in the final material differ from those of the non-stretched porous ceramic plate. The pore size and shape of the porous ceramic plate (eg, glass foam) extends as follows according to an embodiment of the present invention: the average diameter of the pores is less than 1 mm, and the pore shape is averaged. Thus, some dimensions are more asymmetric than others. One dimension is 1.2 times or more and 1.6 times or less, preferably 1.3 times or more and 1.5 times or less, for example, about 1.4 times larger than the other dimensions depending on the ultrasonic wave transmission time. In a third embodiment, the present invention relates to a porous ceramic plate obtained by any of the manufacturing methods in the first embodiment according to the present invention.

[Example 1: Test line]
A glass foam plate was produced according to the first aspect of the present invention. As an example, various glass foam plates were produced by use of an apparatus including a powder loading apparatus. The apparatus includes a first conveyor, an intermediate region including an intermediate (third) conveyor, and an annealing annealing slow kettle including a second conveyor. The glass powder is placed on the foaming conveyor in an amount of 8000 cm ² / g. The length of the foaming oven is 10 m.

  The first conveyor is a heat-resistant steel belt containing a heat-resistant ceramic material and densely packed with powder. The belt linear velocity was about 3 cm / min. The temperature at the top of the foaming furnace was 650 ° C. or more and 670 ° C. or less, and the end of the foaming furnace was 750 ° C. or more and 770 ° C. or less. The intermediate (third) conveyor was a series of water-cooled rolls. The temperature in the intermediate region was 650 ° C. or higher and 680 ° C. or lower at the beginning of the intermediate region. Further, the temperature in the intermediate region reached a maximum of 800 ° C. between the beginning and end of the intermediate region, and was about 700 ° C. at the end of the intermediate region.

The length of the intermediate conveyor was 1 meter. The roll of the intermediate conveyor was driven at a speed about 5% faster than the speed of the second conveyor. The second conveyor is another series of rolls (it is appropriate to use a belt), and the temperature in the annealing cooler is about 600 ° C. at the top of the slow cooler. The temperature was lowered to room temperature (20 ° C. to 40 ° C.) at the end of the kettle. The length of the second conveyor was 22 m. The linear speed of the second conveyor the speed of the first conveyor 5% or more, a rate of more than 10% or more and 15% or higher, thereby, 105 Kg / ^{m 3} of density of the foam glass plates, respectively 5%, 10 % And 15% elongation. The glass foam plate can then be cut in the side, horizontal or lateral direction.

The speeds of the first conveyor, the second conveyor and the intermediate conveyor in these examples were as follows:
The first speed was always about 3 cm / min. To stretch by 5%, 10% or 15%, the second speed is 5%, 10% or 15% faster than the first speed, respectively. The third speed (ie, the speed of the intermediate conveyor) was 5% faster than the second speed. The following results in Table 1 below were obtained for extension to 15%.

  The results in Table 1 show that stretching decreases the K-value and compressive strength. Different results are obtained when the density or ceramics are other.

The inventors have found that the mechanical properties can be improved by setting the speed of the second conveyor to be 20% faster than the conveying speed in the foaming furnace. Thereby, 20% expansion and contraction is possible. In this method, a foam having a thickness of about 16 cm at 120 kg / m ³ was obtained.

An intermediate conveyor is used at a faster speed than the second conveyor, so that the first value associated with the final extension, eg a pre-extension of up to 25%, is a second value lower than the first value, For example, it becomes equal to 20%. As a result, the speed of the first conveyor is 3.18 cm / min, the slow cooling kettle is not damaged, only 10% is subsequently damaged, and the bottom is not defective, and the density is 120 kg / m. ³ and a foamed glass sheet having a thickness of 16 cm can be annealed.

  FIG. 1 schematically shows an apparatus according to an embodiment of the invention. In this figure, the 1st conveyor 1, the 2nd conveyor 2, and the intermediate | middle conveyor 5 are shown. The first conveyor conveys the foam glass through the foaming furnace 3 and conveys the foam glass ribbon to the intermediate conveyor 5. The intermediate conveyor 5 conveys the foam glass ribbon through the intermediate slow cooling furnace 6 and conveys the foam glass ribbon to the second conveyor 2. The second conveyor 2 conveys the foam glass ribbon through the annealing annealing furnace 4.

Claims (17)

a) heat-treating the ceramic particles and the expansion agent in a foaming furnace (3) while conveying the ceramic particles and the expansion agent at a first speed to form a porous ceramic plate;
b) While transporting the porous ceramic plate at a second speed higher than the first speed, the porous ceramic plate is cooled by cooling the porous ceramic plate in the annealing slow cooling pot (4). Annealing and stretching and cooling the porous ceramic plate;
A continuous production method of a porous ceramic plate containing   Before the step (b), the porous ceramic plate is passed through the intermediate conveyor from the foaming furnace (3) to the annealing slow-cooling kettle (4) at a third speed faster than or equal to the second speed. The continuous manufacturing method of the porous ceramic board of Claim 1 which conveys. The difference between the first speed and the second speed is 25% or less,
The continuous production method of a porous ceramic plate according to claim 1 or 2, more preferably 3% or more and 25% or less.   The method for continuously producing a porous ceramic plate according to claim 2 or 3, wherein a difference between the third speed and the second speed is 0% or more and 10% or less of the second speed.   The said porous ceramic board is a glass foam board, The continuous manufacturing method of the porous ceramic board of any one of Claims 1-4. a) a foaming furnace (3) for heat treating the ceramic particles and the expansion agent to form a porous ceramic plate;
The foaming furnace (3) includes a first conveyor (1) adapted for transport at a first speed while heating the ceramic particles and expansion agent to form the porous ceramic plate,
b) including an annealing slow cooling pot (4) for annealing the porous ceramic plate by cooling the porous ceramic plate;
The annealing slow cooler (4) is located downstream from the foaming furnace (3), and is adapted to transport the porous ceramic plate at a second speed higher than the first speed. An apparatus for continuously producing a porous ceramic plate including a conveyor (2).   The intermediate conveyor (5) which moves the said porous ceramic board from the said foaming furnace (3) to the said annealing slow cooling pot (4) before the 2nd conveyor (2) is further included. Continuous production equipment for porous ceramic plates.   The continuous production apparatus for a porous ceramic plate according to claim 7, wherein the intermediate conveyor is adapted to a third speed that is faster than or equal to the second speed.   The first conveyor (1) and the second conveyor (2) so that the difference between the second speed and the first speed is 25% or less of the first speed, preferably 3% or more and 25% or less. The continuous production apparatus for a porous ceramic plate according to any one of claims 6 to 8, which is adapted to be driven.   The porous ceramic plate according to claim 8 or 9, wherein a difference between the third speed and the second speed is 0% or more and 10% or less of the second speed, preferably 0% or more and 5% or less. Continuous manufacturing equipment.   The said 1st conveyor is a continuous manufacturing apparatus of the porous ceramic board of any one of Claims 7-10 adapted to the temperature tolerance higher than a 2nd conveyor. The first conveyor is adapted to have a temperature tolerance of up to 900 ° C,
The said 2nd conveyor is a continuous production apparatus of the porous ceramic board of Claim 11 adapted so that the upper limit may have the temperature tolerance of 600 degreeC.   The continuous production apparatus for a porous ceramic plate according to any one of claims 7 to 12, wherein the intermediate conveyor includes a roll.   8. The intermediate conveyor is disposed at the head of the annealing furnace or in an intermediate cooling tank disposed between the foaming furnace and the head of the annealing furnace. The continuous manufacturing apparatus of the porous ceramic board of any one of -13.   The continuous manufacturing apparatus of the porous ceramic board of any one of Claims 7-14 in which the said intermediate conveyor has temperature tolerance in the range of 600 to 800 degreeC. A porous ceramic plate having a pore structure,
A porous ceramic plate in which the pores are asymmetrical in which one dimension is 1.2 times or more and 2.8 times or less than other dimensions. Has an asymmetric pore structure,
The porous ceramic board obtained by the continuous manufacturing method of the porous ceramic board of any one of Claims 1-5.

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